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s Sheets-Sheet 1 (No Model.)

J MILLS WATER TUBE STEAM BOILER.

No. 423,790, Patented Mar. 18. 1890.

N. Puma MUM mamn c.

a Sheets- Sheet 2.- I

(No Model.)

Patented Mar. 18, 1890.

N. PETERS. Phfllo-lilhognphar. Wadi-M510. D. C.

N TED STATES ATENT OFFICE.

WATER-TUBE STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 423,790, dated March 18, 1890.

Application filed November 8, 1889. Serial No. 329,693. (No model.) Patented in England May 12, 1888, No. 7,077, and in France May 10, 1889, No. 193,049-

To all whom it may concern.-

Be it known that I, JOHNSON MILLS, a subject of the Queen of Great Britain, and a resident of Prestwich, in the county of Lancaster, England, have invented certain new and-useful Improvements in WVater-Tube Steam-Boilers, (for which I have obtained a patent in Great Britain, No. 7,077, dated May 12, A. D. 1888, and in France, No. 198,049, dated May 10, 1889,) of which the following is afull, clear, and exact specification.

The improvements which are the subject of this invention relate to the application to water-tube steam -boilers of a water-chambered fire box orboxes,which are or may be of the flue-tube construction or other suitable form, in combination with tubes and pipes for connection with and to said water-tube steamboilers, these water-chambered fire-boxes in their connection to and combination with wator-tube steam-boilers being placed in the position usually occupied by the furnaces of Water-tube steam-boilers. This combination of fire box or boxes with the tubes or pipes attached thereto are connected to and in combination with the several tubes and drums of water-tube steam-boilers.

The objects of this invention are to utilize in the generation of steam the greatest possible amount of heat given ofi in radiation while the fuel is in combustion and to save the very heavy and frequent expense of renewing the brickwork which is requisite to furnaces of water-tube steam-boilers.

By the arrangement of fluefurnace, which in this invention is formed by the water chamber or tube which surrounds the fire, the radiant heat is more efficiently absorbed and utilized in the production of steam in lieu of being largely wasted, as hitherto, by absorption with brick walls, which in the present form of construction inclose the furnaces of water-tube steam-boilers, and the hot gases which are produced by the complete combustion of the fuel passed forward through the several sets or nests or parts of the watertube steam-boiler and are thoroughly utilized.

In order more clearly to describe this my invention, I have annexed hereunto three sheets of drawings. In the several views therein shown similar letters refer to similar parts. 7

Figure 1 is a transverse section, andFig. 2 a longitudinal section, of awater-tube steamboiler provided with my improvements. Figs. 3 and 4 and 5 and 6 are respectively transverse and longitudinal sections of the same with slight modifications. Figs. 7 and 8 are transverse and longitudinal sections, which will be hereinafter more particularly referred to. Figs. 9 and 10 are longitudinal sections showing modifications.

The sectional lineof Fig. l is taken through the line A B 011 Fig. 2, and the sectional line of Fig. 2 is drawn through the line C D on Fig. 1.

In the drawings, A is the steam and water drum.

B and B are tubes which are parts of existing forms of water-tube steam-boilers, and

through which the water circulates.

b and b are tubes which I employ to form connections between the water-chamber e and the drums, tubes, or slabs of Water of watertube steam-boilers. y

c is the flue-furnace, which I construct, preferably, of a cylindrical form, and which maybe either a flanged-seam furnace, as shown in Fig. 8, or Foxs patent corrugated flue, as represented in Figs. 1 to 6, or of any other suitable construction.

d is the water-casing, which I form of steel or iron of any strength that maybe required. The space ethus left between the flue-furnace c and the outer casing or shell cl, and which may Vary more or less in capacity according to requirements, I use as a water-chamber. The heat which rises from the combustion of the fuel in the furnace c is utilized in the generation of steam from the water contained. in the chamber 0, which surrounds the furnace 0, instead of being absorbed and wasted by the brick walls of which the furnaces in watertube steamboilers are composed. As the water in the chamber 6 is increased in tem- 5 perature it becomes expanded and sets up a circulation through the several parts of the boiler.

I place a mud and water drum f in a transverse position at the rear end of the boiler, :00

and I connect said mud and water drum with the water-chamber e of the flue-tube fire-box by means of the tubes b and to rear end of steam and water drum d and the tubes b by meansbf long nipples b, which are expanded in their respective positions. In forming the connection between the upper part of waterchamber'e of flue-tube fire-box and the front portion of steam and water drumd any preferable means may be employed.

The connection between the water-chamber e of flue-tube fire box and the mud and water drum f may be formed either by means of tubes 75 as shown in Fig. 2, hereinbefore described, or with flanged wrought-iron, steel, or other metal tubes or pipes 19 as shown in Figs' 9 and 10, Sheet 8. The tubes 19 or pipes 11 may also be connected with the steam and water drum at the rear end of the boiler by means of tubes or pipes direct in lieu of passing through the tubes 1) and rear headers.

The hereinabove-described flue tube firebox may be supported by girders J, by brackets, or by other suitable appliances, or may .a

be supported either whole or in part by the tubes 1), which connect said fire-box to steam and water drum. Having now particularly described and ascertained the nature of my said invention and in What manner the same is to be performed, I declare that what I claim is- In a sectional tube-boiler having inclined water-tubes connected to the headers, said JOHNSON MILLS.

iVitnesses:

J ONN. GBESTY, THOMAS PRESCOTT. 

